title: Effect of type and concentration of ballasting particles on sinking rate of marine snow produced by the appendicularian Oikopleura dioica.
abstract: Ballast material (organic, opal, calcite, lithogenic) is suggested to affect sinking speed of aggregates in the ocean. Here, we tested this hypothesis by incubating appendicularians in suspensions of different algae or Saharan dust, and observing the sinking speed of the marine snow formed by their discarded houses. We show that calcite increases the sinking speeds of aggregates by ~100% and lithogenic material by ~150% while opal only has a minor effect. Furthermore the effect of ballast particle concentration was causing a 33 m d(-1) increase in sinking speed for a 5×10(5) µm(3) ml(-1) increase in particle concentration, near independent on ballast type. We finally compare our observations to the literature and stress the need to generate aggregates similar to those in nature in order to get realistic estimates of the impact of ballast particles on sinking speeds.
authors.affiliation: Centre for Ocean Life, National Institute for Aquatic Resources, Section for Oceanography and Climate, Technical University of Denmark, Charlottenlund, Denmark ; UPMC, Université Paris06, UMR 7093, Laboratoire d'Océanographie de Villefranche-sur-Mer, Observatoire Océanologique de Villefranche sur Mer, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Lombard
authors.forename: Lionel
authors.initials: L
authors.lastname: Guidi
authors.forename: Thomas
authors.initials: T
authors.lastname: Kiørboe
mesh_terms: D000818:Animals; D002244:Carbon / Q000378:metabolism; D057965:Carbon Sequestration / Q000502:physiology; D009792:Oceans and Seas; D010316:Particle Size; D012623:Seawater; D014561:Urochordata / Q000378:metabolism* / Q000502:physiology*
chemical_list: D002244:Carbon